Question 1

Which of the following best describes the 'fluid mosaic model' of the plasma membrane?

Accepted Answer

A dynamic structure with proteins embedded in or attached to a bilayer of phospholipids, allowing lateral movement.

Question 2

A researcher wants to observe the 3D surface structure of a pollen grain. Which type of microscopy should they use?

Accepted Answer

Scanning electron microscopy (SEM)

Question 3

Which of the following statements about passive transport is correct?

Accepted Answer

It involves the movement of substances down their concentration gradient without energy input.

Question 4

A cell is placed in a solution and water moves into the cell, causing it to swell. Which term best describes the solution?

Accepted Answer

Hypotonic

Question 5

Which of the following is an example of active transport?

Accepted Answer

Sodium-potassium pump moving Na$$^+$$ out of and K$$^+$$ into a neuron using ATP

Question 6

Which process is responsible for the uptake of cholesterol into animal cells?

Accepted Answer

Receptor-mediated endocytosis

Question 7

A plant cell uses a proton pump to create a gradient of H$$^+$$ ions outside the cell. This gradient is then used to transport sucrose into the cell against its concentration gradient. What is this type of transport called?

Accepted Answer

Cotransport (secondary active transport)

Question 8

Which of the following best explains why cells are typically small in size?

Accepted Answer

To maximize the surface area-to-volume ratio for efficient exchange of materials.

Question 9

A nerve cell has a surface area of $$A = 2lw + 2lh + 2wh$$ and a volume of $$V = lwh. If $$the cell is 125 units long, 1 unit wide, and 1 unit high, what is its surface area-to-volume ratio?

Accepted Answer

$$\frac{252}{1}$$

Question 10

Which of the following is NOT a function of the endomembrane system?

Accepted Answer

Synthesizing ATP via oxidative phosphorylation

Question 11

Which of the following best distinguishes prokaryotic cells from eukaryotic cells?

Accepted Answer

Eukaryotic cells have membrane-bound organelles, including a nucleus.

Question 12

Which of the following statements about exocytosis is correct?

Accepted Answer

It involves the fusion of vesicles with the plasma membrane to release contents outside the cell.

Question 13

A scientist wants to study the process of protein translation from mRNA. Which cell fraction should they isolate?

Accepted Answer

Ribosomes

Question 14

Which of the following is a correct description of pinocytosis?

Accepted Answer

The cell 'gulps' extracellular fluid and dissolved solutes into tiny vesicles.

Question 15

Which of the following best describes the role of the cytoskeleton?

Accepted Answer

It organizes structures and activities in the cell, providing support and facilitating movement.

Question 16

A patient with hypercholesterolemia has high blood cholesterol due to defective LDL receptors. Which cellular process is directly affected?

Accepted Answer

Receptor-mediated endocytosis of LDL

Question 17

Which of the following best explains why the sodium-potassium pump is not considered a cotransporter?

Accepted Answer

It uses ATP directly to move ions against their gradients, rather than coupling the movement of one ion down its gradient to another up its gradient.

Question 18

Which of the following is a real-life example of bulk transport in animal cells?

Accepted Answer

White blood cells engulfing bacteria via phagocytosis

Question 19

Which of the following best describes the function of mitochondria?

Accepted Answer

They convert energy from one form to another, primarily producing ATP from glucose.

Question 20

A cell biologist uses differential centrifugation to separate cell components. Which property is primarily used to separate these components?

Accepted Answer

Their size and density

Membrane Structure and Function & Cell Structure: Study Notes for General Biology

Guida di studio - Domande di pratica

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